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Getting Rid of Eye Drops for Glaucoma

July 28, 2014

Duke engineers and ophthalmologists are developing a long-lasting injection to treat glaucoma

Imagine yourself at age 80, fumbling for the small vial of eye drops your ophthalmologist prescribed for your glaucoma. It’s five in the afternoon, you can’t remember whether you put them back in the bathroom or the bedside table after your last application, and you worry that your shaking hands will once again leave the drops on your cheeks instead of in your eyes. And even if you’re successful, only a small amount of medication will actually reach its intended target deep within the eye.

Jennifer West, a professor of biomedical engineering and mechanical engineering and materials science in Duke’s Pratt School of Engineering, and Molly Walsh, MD, an ophthalmologist and researcher with Duke Eye Center, want to make life easier for the tens of millions of glaucoma sufferers worldwide. Through collaborations with fellow Duke ophthalmologist Stuart McKinnon, MD, PhD, the team has created a device known as the Retroject RJT1125 that stabilizes the eyeball and allows a glaucoma drug to be injected into the veins near the iris.

Walsh has been developing the RJT1125, which is the size of a half-dollar and fits perfectly over the patient’s eye to stabilize it for an injection. The target is the episcleral vein that provides direct access to an area called Schlemm’s canal, which is where glaucoma medications need to be delivered.

Because blood in the vein is normally flowing away from the eye, the Retroject puts gentle pressure on the vein, making it flow backward and inside the eye. The entire process can take less than a minute and be done during a regular check-up by an ophthalmologist.

“One of the issues, however, is that you don’t want patients to have to come in too often to get these injections,” explained West. “Even though the procedure is essentially painless, it’s still a trip into the doctor, which can be difficult for many patients. So we are looking for ways to inject a long-acting medication.”

West wants to figure out how to make the injection last for months. To do this, she is turning to nanoparticles. The tiny spheres can be made to recognize chemical signals unique to Schlemm’s canal and latch onto the walls in only that location. Then, over time, the nanoparticles can slowly release the medication that they have been pre-loaded with.

The end goal is to eliminate the need for daily eye drops.

Although the nanoparticles are years away from public use, the Retroject device is on a fast track for testing in human clinical trials this month, thanks in part to support from the Duke Translational Medicine Institute (DTMI), whose mission is to speed up the translation of laboratory science into clinical care. The project gained further momentum in 2013 from a Duke/Coulter Translational Research Partnership grant, which supports collaborative research projects involving biomedical engineering and clinical medicine at Duke. The award provided financial support as well as advice and direction on regulatory pathways and commercialization strategies.

Through the Coulter award, Duke provided West and Walsh with a project leader, Kristi Viles, PhD, to help the researchers along the path toward success. This service is offered through the Duke Translational Research Institute (DTRI).

“The infrastructure and guidance Kristi provides are immensely helpful,” Walsh said. “This has pushed our technology forward in ways I could not have done alone.”

Now, the team has received a second Coulter award, which will fund continued investigation of the safety and efficacy of the RJT1125 and the nanoparticles. The injection technique itself is already in the first human trial to show that it can be safely placed on the eye and an injection can be safely completed, while the anti-glaucoma nanoparticles are in animal trials. The investigators will also work with the Duke Translational Research Institute to apply for regulatory approvals from the FDA and prepare applications for follow-on funding from the NIH Small Business Technology Transfer (STTR) program.